System and method for analyzing a network and/or generating the topology of a network

ABSTRACT

The invention relates to a system and method called autotopology of a network or advertising based network management which enables the analysis and automatic graphical and hierarchical representation of any hierarchical or flat network topology, especially a switched Ethernet (SE). The autotopology can be used for self-configured networks (for example by using zeroconf) and for any otherwise configured networks, especially using DHCP or manually configured networks. The use of zeroconf is called autoconfiguration. Autoconfiguration and autotopology enable a comfortable and safe administration of a network. Administration of a self-configured network using the autotopology data proceeds in a separate and low-priority sub-network (link local) so that the productive operation of the network remains undisturbed. The topology of the network is used as a clear possibility of administering a network. Administration of the network is possible immediately after determination of the topology.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage of International ApplicationNo. PCT/DE03/00199, filed Jan. 24, 2003 and claims the benefit thereof.The International Application claims the benefits of German applicationNo. 10204826.6 filed Feb. 6, 2002, both of the applications areincorporated by reference herein in their entirety.

FIELD OF INVENTION

The invention relates to a system and method for analyzing a networkand/or generating the topology of a network.

BACKGROUND OF INVENTION

With networks, the elements in the network generally have a uniquenetwork address for the purpose of exchanging data, by means of which itis possible to exchange data selectively. This situation enables theelements in the network, for example switches, computers, etc., to makethemselves known by sending their network address to all the otherelements in the network. Until now it has only been possible todetermine the topology of such a network manually, i.e. by a personand/or by calling on the assistance of very time-consuming iterativemethods.

SUMMARY OF INVENTION

The object of the present invention is to simplify and automate theanalysis and representation of the topology of any arbitrary network forthe exchange of data, so that the need for human assistance can beobviated.

This object is achieved by a method for analyzing and representing thetopology of a network for the exchange of data, consisting of at leasttwo elements, to each of which is assigned at least one network address,whereby each element in the network is automatically registered, itshierarchical position in the network is determined by reference to thenetwork address of the element, and from this the structure of thenetwork is generated and saved.

This object is achieved by a system for the analysis and representationof the topology of a network for the exchange of data, consisting of atleast two elements, to each of which is assigned at least one networkaddress, whereby the system automatically registers each element in thenetwork, determines its hierarchical position in the network byreference to the network address of the element, and from this generatesand saves the structure of the network.

A particularly advantageous embodiment of the invention is characterizedby the fact that the topology of the network is held as data in theformat of a markup language, and the graphical representation of thenetwork topology is generated by reference to this data. Saving the datain the format of a markup language enables the data thus stored to bemade available without problem to other systems for the purposes ofrepresentation and/or further processing, in particular over or by meansof an intranet or the internet, as applicable. In doing this, it isadvantageous to use as the markup language the Extended Markup Language(XML), Hypertext Markup Language (HTML) or related dialects. Here, anexceptionally advantageous form of embodiment is to save the topology ofthe network as a file in XML format because, when this markup languageis used, it is possible to effect a particularly rapid representation,and hence time-saving.

It is especially advantageous if the graphical representation of thenetwork's topology is in the form of a hierarchical tree structure. Agraphical representation permits a rapid overview of the topology of anetwork, and hence its structure, whereby the hierarchical treestructure gives a simplified, and hence improved, overview of the linksbetween individual network elements and/or their interdependencies.

A further advantageous form of embodiment of the invention ischaracterized by the fact that the topology of the network is constantlybeing checked, compared to the previous current state, and each timethere is a change to the topology the current topology of the network isautomatically generated and stored as a file. This enables continuousonline checking of the network topology, which can if required be calledup at any time and displayed graphically. A particular advantage whichthis brings is that the up-to-date details of the topology of a networkare continuously available, but this can be effected in the background,i.e. without a display screen. Only when it becomes necessary need acomputer with a display screen be connected into the network, to call upand display on the screen the continuously updated data about thetopology of the network, for example for maintenance purposes.

A further particularly advantageous form of embodiment of the inventionis characterized by the fact that the structure of the network is savedas a file and that the file, containing the current data for therelevant topology of the network can be called up and/or the topology ofthe network can be displayed graphically. In addition, it isparticularly advantageous if the graphical representation of thetopology of the network is used for the administration and/or theconfiguration of the elements in the network and/or the network itself.This makes it possible to administer and/or configure other elements orthe network itself from any point in the network. This makes it possibleto intervene immediately at any point in the network, regardless ofgeographical location, when current situations arise, for examplecritical ones, because the current topology of the network is availableat any point in time.

A further advantageous form of embodiment of the invention ischaracterized by the fact that it is possible to generate automaticallythe topology of two or more independent subnetworks which are linked toeach other by at least one element, and to display it in a graphicalrepresentation, in which network islands form the first level of thehierarchical structure. This also makes it possible to automaticallyregister several networks, so-called subnetworks, even if they arelinked together only by an individual computer or element, asapplicable, and thus enables the topology of several subnetworks to beautomatically shown in a single graphical representation of thetopology. The advantage of this form of embodiment is that it providesan overview of several subnetworks in a single representation, so thatit is not necessary to swap separately into each of the subnetworksconcerned.

An exceptionally advantageous form of embodiment of the invention ischaracterized by the fact that each element in the network ischaracterized in each case by at least one hyperlink within the dataitems which specify the topology of the network, and its interactionwith a network element is effected by means of this hyperlink, wherebythe interaction using the hyperlink can be performed from within thegraphical representation of the topology. It is furthermore ofparticular advantage if the interaction with a network element iseffected by means of hyperlinks over the internet and/or intranet. Theadvantage of this is that each network element can be reached by aninternet connection, i.e. each element is addressed and symbolized by aninternet or intranet page, using the appropriate internet address, aso-called URL address. A click on this hyperlink then makes availablefor each element one or more internet or web pages, on which theappropriate configuration or administration tasks can be completed.

A form of embodiment of the invention which is of further advantage ischaracterized by the fact that it is possible to show the individualelements of the network in different colors in the graphicalrepresentation of the topology of the network, where the color of therepresentation indicates the status of the element concerned. Here, atleast three different statuses are possible for each element, inparticular green for “link to element is in order”, red for “link toelement is faulty” and yellow for “diagnosis in progress for theelement's link”. All other possible color combinations are, of course,conceivable and possible. This not only gives one an overview of thecurrent topology of the network but, in addition, it makes possible adiagnosis of the individual elements of the network and hence anexceptionally rapid and cost-effective analysis can also be performed,for example in the event of a fault. Using the hyperlink access to theconfiguration or administration data concerned, it is also possible tocarry out maintenance, in particular remote maintenance, for apossibly-faulty link to the element.

A further advantageous form of embodiment of the invention ischaracterized by the fact that the topology of any arbitrary switchedEthernet can be automatically analyzed and represented. This is ofparticular advantage because a switched Ethernet is very often used, inparticular, in the case of industrial plants, production machinery,automated facilities, so that high costs are incurred for checking,analysis and maintenance activities, which are substantially reduced bythe invention. This applies also to the use in manufacturing and/orprocess automation systems of the method disclosed, which also leads tosubstantial cost reductions.

The invention is described and explained in more detail below byreference to the exemplary embodiments shown the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

These show:

FIG. 1 a schematic representation of a first form of embodiment for anetwork, and

FIG. 2 a schematic diagram of the advertising of a new element in anetwork.

DETAILED DESCRIPTION OF INVENTION

The schematic representation as in FIG. 1 shows a first form ofembodiment for a network, for example a switched Ethernet with severalelements. Further examples of such networks are: Fieldbus, Profibus,Ethernet, Fast Ethernet, Industrial Ethernet or Fire-Wire, but alsoclocked data networks such as the Isochronous Real-time Ethernet, forexample, and combinations of them. The networks used can either beequipped or not with real-time characteristics, such as clocksynchronization and equidistance. In FIG. 1, for example, severalcoupling elements, also referred to as switches, of which for the sakeof presentational clarity only Switch 2 is shown, can be linked witheach other over data lines, of which for the sake of presentationalclarity only the data lines 6 and 6 a are shown. Thus such data linesare used to connect the switches to nodes, for example industrialcomputers, PCs or other computers, etc., of which for the sake ofclarity only node 3 is shown. The nodes can set up connections over thedata lines, exchange data and clear the connections again in acontrolled manner. In addition, each node must be identifiable.Furthermore, the nodes can be connected to other elements, for example aprogrammable logic computer (PLC) and its terminal devices 4, via othernetworks, for example the Profibus network 5. Examples of such elementsare central programmable controllers, programming, configuration oroperating devices, peripheral devices such as input/output modules,drives, actuators, sensors, programmable logic controllers (PLCs) orother control units, computers or machines which exchange electronicdata with other machines, in particular which process data from othermachines. Here, the term control unit is to be interpreted as any typeof closed or open loop controller.

In the present exemplary embodiment, one computer 1, which isparticularly singled out and which is referred to below as the Manager,is linked via the data line 6 a to the Switch 2, which is part of thenetwork already described. The Manager 1 contains the functionality topermit the analysis and automatic creation and hierarchicalrepresentation of any arbitrary network topology, hierarchical or flat,in particular for a “switched” Ethernet (SE) and in particular also forthe network shown schematically in FIG. 1. This procedure, orfunctionality of this type, as applicable, is referred to below asautotopology.

In order to arrive at such functionality, two “discovery” methods—SNMPtop-down and SSDP bottom-up—have been combined and improved. One thenalso refers to “advertising based network management”

In any arbitrary network, each node in the network has two differentaddresses, for example in accordance with the ZEROCONF standard orZEROCONF specification as applicable, so-called IP addresses where IPmeans Internet Protocol, of which one IP address is used for the ongoingoperation of the node concerned within the network. This is thereforealso referred to as the “productive” IP address, because it can be knownto the other network elements, and therefore can be queried or addressedduring ongoing operation. This address is therefore “routable”. On theother hand the second, secondary, address is not “routable” for theother network elements, or not for all of the network elements. Such anaddress is also referred to as, for example, a “local link” IP address(LL-IP address).

The “productive” IP address may be allocated to the network elementseither automatically by a network protocol, in particular an internetprotocol such as for example DHCP (Dynamic Host Configuration Protocol),or may also be allocated manually. This “productive” IP address islinked to the hardware address concerned for the network card in thecomputer concerned, also called the MAC address, which is unique aroundthe world. The nodes may themselves autonomously assign the secondaryLL-IP addresses, but the uniqueness of the secondary LL-IP addressesmust remain guaranteed. They can also be assigned manually. This meansthat, for example, when two or more subnetworks are connected together a“reassignment” may be necessary, i.e. a reassignment of the secondaryLL-IP addresses, if the secondary LL-IP addresses are duplicated. Thesecondary LL-IP addresses give nodes the ability to latch in as newelements into a network which is running “productively”, such as thatshown by way of example in FIG. 1, and by the use of their secondary“local-link” IP addresses to register and declare themselves, withoutdisrupting the productive operation of the network, which is beinghandled using the “productive” IP addresses of the network elements.

In FIG. 2, a new network element, the node 7, announces its connectionto the network by sending out so-called IP multicast telegrams 10 a, 10b to all the available network elements, in this case the Switch 8 andthe Manager 9; this is also referred to as an “advertisement” of thenetwork node. For example, if the Simple Service Discovery Protocol(SSDP) is being used, it is possible to find all the switches which arein the network, in particular Switch 8 and the Manager 9, by certaincommands, for example “ssdp:notify” or “ssdp:m-search”. This procedureis also referred to as “discovery”. All the switches, in particularSwitch 8 and/or in addition the Manager 9, are informed of the secondary“local link” IP address in this way. If other protocols are used,appropriate commands valid under these protocols will be used.Obviously, the same mechanism can be used in an analogous way inderegistering a network element, for example the node 7, from thenetwork. Using the secondary “local link” IP address, the switches, inparticular Switch 8, can query the MAC addresses concerned for newnetwork elements belonging to the switches, for example for node 7 bymeans of a query 11 about the MAC address of node 7, and the MAC addresssent back as a reply 12 can be used to make entries 13 for node 7 intables, so-called “learning tables”.

Each switch in the network, in particular also Switch 8, maintains itsown “learning tables” in which are indexed the MAC addresses and thecorresponding “productive” IP addresses of each of the network elements,for example node 7, connected to the individual ports of the switchconcerned.

Through “discovery” procedure, the Manager 9 knows the secondary “locallink” IP addresses of all the network elements, in particular of node 7,and each switch, in particular Switch 8, together with the MAC addressesand the “productive” IP addresses of all the nodes which are connectedto the ports on the switch concerned, in particular on node 7.

The Manager 9 determines the MAC addresses of all the networkcomponents, in particular of node 7, which have been “learned” at aparticular port on a switch, in particular Switch 8, i.e. which havebeen indexed in the appropriate “Learning Tables”, by means ofappropriate commands, for example if the Simple Network ManagementProtocol (SNMP) is being used by an SNMP GET query 14 to the switch SNMPagent, Switch 8. This latter supplies the desired MAC and/or“productive” IP addresses for the network elements which are connectedto the corresponding port, in particular the addresses of node 7, as anSNMP Get Response 15 to the SNMP GET query 14.

The Manager 9 then compares the “local link” IP addresses, determinedfor example from the “ssdp:notify” telegrams, in particular for node 7,with the MAC addresses obtained for example from the SNMP Get Response15, and from the comparison of these items of data automaticallygenerates the topology or hierarchy, as applicable, of the network,which is filed and saved in the form of a hierarchical tree in a file16. This operation is referred to as autotopology. In doing so, it isadvantageous if the topology of the network is specified in the markuplanguage XML, but other markup languages which are commonly used on theinternet, in particular HTML, XHTML etc., are also possible andconceivable. The graphical representation of the topology of the networkunder consideration is produced (for example using a user-defined OLEcontrol element, that is an OCX file) on the basis of this generatedfile 16, for example in the markup language XML. This makes it possiblefor any browser with the capability to interpret the markup language,for example XML, to display the topology of the network. It isadvantageous if the topology is constructed as a hierarchical treestructure, which will make it possible to represent unconnectednetworks, because in such a representation network islands form thefirst level of the XML tree.

The procedure described for the initial registration of a networkelement, more specifically node 7, can of course also be used in theopposite situation where the Manager 9, or more specifically theautotopology functionality, is connected to a network which alreadyexists.

The manager, for example Manager 9, continuously checks the topology ofthe network, compares it against the previous current state, and foreach change in the topology, for example the registration of a newnetwork element or deregistration of an old one, automatically generatesthe current topology of the network and files it in a file. This enablescontinuous online checking of the topology of the network, which can becalled up and displayed graphically at any time when it is required. Aparticular advantage arising from this is that the current topology of anetwork is continuously available as a file, but this can be effected inthe background, i.e. without the need for a display screen. Not until itis required, for example for maintenance activities, need a computer beconnected into the network and the continuously updated data about thetopology of the network be called up and displayed graphically on thescreen.

A first advantageous form of embodiment is the identification orsymbolization of the elements of the network, in each case by at leastone hyperlink, for example an internet-compatible URL and/or WWWaddress, etc., within the data which specifies the topology of thenetwork, for example the XML data. This makes it possible to interactwith each network element using the hyperlink which symbolizes theelement, whereby the interaction using the hyperlink can be effected, inparticular, from within the graphical representation of the networktopology. It is, furthermore, particularly advantageous that, wheninternet or intranet addresses are used as the hyperlinks, theinteraction with a network element is effected by means of a hyperlinkover the internet and/or the intranet. The advantage of this is thateach network element can be reached via an internet connection, using ahyperlink, i.e. each element is addressed and symbolized by an internetor intranet page using respectively the corresponding internet orintranet address, a so-called URL and/or WWW address. A click on thishyperlink from within the graphical representation of the topology makesavailable for each element one or more internet or web pages, asapplicable, on which the appropriate configuration or administrationtasks can be completed, i.e. the graphical representation of thenetwork's topology can be used for the administration and/orconfiguration of the elements in the network and/or the network itself.This makes it possible to administer and/or configure other elements orthe network itself from any arbitrary places in the network, so that itpossible to intervene immediately at any arbitrary place in the network,regardless of geographical location, when relevant situations arise, forexample critical ones, because the current topology of the network isavailable at any point in time.

A further very advantageous form of embodiment is characterized by thefact that it is possible to show the individual elements of the networkin different colors in the graphical representation of the topology ofthe network, where the color of the representation indicates the statusof the element concerned. Here, at least three different statuses arepossible for each element, in particular green for “link to element isin order”, red for “link to element is faulty” and yellow for “diagnosisin progress for the element's link”. All other possible colorcombinations are, of course, equally conceivable and possible. This notonly gives one an overview of the current topology of the network but,in addition, it enables diagnosis of the individual elements of thenetwork and hence an exceptionally rapid and cost-effective analysis canalso be performed, for example in the event of a fault. Using thehyperlink access to the configuration or administration data concerned,it is also possible to carry out maintenance, in particular remotemaintenance, for a possibly-faulty link to the element.

The system and method of network autotopology, also referred to as“Advertising based Network Management” enables an analysis and automaticgraphical and hierarchical representation to be produced for anyarbitrary network topology, hierarchical or flat, in particular for a“switched” Ethernet (SE).

Here, autotopology can be used both for networks which areself-configured (for example by the use of ZEROCONF) and also fornetworks configured in any alternative way, for example using DHCP, ormanually configured networks. The use of ZEROCONF is referred to asautoconfiguration.

Autoconfiguration and autotopology make user-friendly and secureadministration possible for a network. The administration of aself-configured network by reference to the autotopology data iseffected in a separate and lower-priority subnetwork (local linksubnetwork) so that the productive operation of the network isunaffected.

Immediately after the determination of its topology, the network can beadministered.

Interaction with the network components which are to be administered iseffected by a URL, i.e. for example a hyperlink to an internet address,within the data which specifies the network topology.

Legacy systems, that is systems which have nor yet implemented thepresent technology, are added in manually.

Autotopology is permanently “ONLINE”. The URLs for the networkcomponents which are to be administered are, for example in an XMLbrowser, shown on a colored background. A click on the URL for a networkcomponent accesses the web page which the device offers foradministrative purposes.

The invention disclosed can be used with advantage for and/or during themonitoring, closed and open loop control of, and in, packing machinery,presses, plastic injection molding machines, textile machinery, printingmachinery, machine tools, robots, handling systems, woodworkingmachinery, glass processing machinery, ceramic processing machinery andlifting equipment.

1. A method for analyzing a network and generating the topology of saidnetwork for exchanging electronic data, the method comprising: providingat least two elements of the network, wherein each of the elements ofthe network is assigned at least one network address; automaticallyregistering each element of the network; determining the hierarchicalposition of an element within the network by reference to the networkaddress of the element; generating data indicative of the topology ofthe network, said data comprising a markup language, wherein eachrespective element in the network is uniquely assigned a respectivehyperlink in the data which indicates the topology of the network, andwherein a user's interaction with each respective network element iseffected by the assigned hyperlink; processing said data to generate agraphical representation of the network's topology, wherein saidgraphical representation is in the form of a hierarchical treestructure, wherein the user's interaction with each network elementusing the hyperlink is effected from within a graphical representationof the topology of the network, wherein the elements in the network areshown in different colors in a graphical representation of the topologyof the network, and wherein the color of the representation is selectedto indicate a present status of each respective element, wherein foreach respective element three different statuses are available, whereina first status of the respective element consists of an indication thata link to the respective element is available, wherein a second statusconsists of an indication that a link to the respective element isfaulty, and wherein a third status consists of an indication that a linkto the respective element is undergoing diagnostics; continuouslymonitoring a present status of the topology of the network; comparingthe present status of the topology of the network relative to a previousstatus of the topology of the network; based on a result of saidcomparing, determining at least one change in the present status of thetopology of the network relative to the previous status of the topologyof the network; and upon determining an occurrence of at least onechange in the present status of the topology of the network, updatingthe graphical representation of the topology of the network to includesaid at least one change, including a color change corresponding to achange in the status of each respective element.
 2. The method inaccordance with claim 1, wherein the markup language is Extended MarkupLanguage (XML), Hypertext Markup Language (HTML) or a related dialect.3. The method in accordance with claim 1, wherein the structure of thenetwork is saved as a file, and wherein the file which comprises therelevant current data for the topology of the network can be called upfrom arty arbitrary element in the network and the topology of thenetwork can be shown in graphical form.
 4. The method in accordance withclaim 1, wherein a graphical representation of the topology of thenetwork is used for administering and/or configuring the elements of thenetwork and/or the network itself
 5. The method in accordance with claim1, wherein the topology of two or more independent subnetworks, each ofwhich is linked to the others by at least one element, is automaticallygenerated and can be represented graphically in a display.
 6. The methodin accordance with claim 1, wherein an interaction with a networkelement is performed via internet and/or intranet by a hyperlink.
 7. Themethod in accordance with claim 1, wherein the topology of any arbitraryswitched Ethernet is automatically analyzed and represented.
 8. Themethod in accordance with claim 1, wherein the method is used in amanufacturing system and a process automation system.
 9. The method inaccordance with claim 1, further comprising: saving the structure of thenetwork.
 10. A system for the analysis of a network and the generationof the topology of said network for the exchange of electronic data, thenetwork having at least two elements, each of which is assigned at leastone network address, the system comprising: a mechanism forautomatically registering each element in the network, and fordetermining its hierarchical position within the network by reference tothe element's network address; a mechanism for generating the topologyof the network as data in the format of a markup language; a mechanismfor processing said data to generate a graphical representation of thetopology of the network; a mechanism for representing the topology ofthe network in the form of a hierarchical tree structure; a mechanism touniquely characterize each respective element of the network by arespective hyperlink in said data; a mechanism to allow a user'sinteraction with a network element to be effected by the respectivehyperlink, wherein the interaction using the hyperlink is carried outfrom within a graphical representation of the topology of the network; amechanism for showing the elements in the network in different colors ina graphical representation of the topology of the network, wherein thecolor of the representation indicates the status of the elementconcerned, wherein the elements in the network are shown in differentcolors in a graphical representation of the topology of the network, andwherein the color of the representation is selected to indicate apresent status of each respective element, wherein for each respectiveelement three different statuses are available, wherein a first statusof the respective element consists of an indication that a link to therespective element is available, wherein a second status consists of anindication that a link to the respective element is faulty, and whereina third status consists of an indication that a link to the respectiveelement is undergoing diagnostics; a mechanism for continuously checkingthe topology of the network, for comparing it with the previous presentstate and, for each change in the topology, automatically generating andsaving the present topology of the network; and a mechanism for updatingthe graphical representation of the topology of the network to includeeach change in the topology of the network, including a color changecorresponding to a change in the status of each respective element. 11.The system in accordance with claim 10, wherein the markup language usedare Extended Markup Language (XML), the Hypertext Markup Language (HTML)or a related dialects.
 12. The system in accordance with claim 10,further comprising: a mechanism for saving the structure of the networkas a file, and that the file which comprises the relevant current datafor the topology of the network can be called up from any arbitraryelement in the network and the topology of the network can be shown ingraphical form.
 13. The system in accordance with claim 10, furthercomprising: a mechanism for using a graphical representation of thetopology of the network for the administration and configuration of theelements of the network and/or the network itself.
 14. The system inaccordance with claim 10, further comprising: a mechanism forautomatically generating the topology of two or more independentsubnetworks, each of which is linked to the others by at least oneelement, and for graphically representing the topology.
 15. The systemin accordance with claim 10, further comprising: a mechanism forcarrying out interactions with a network element using a hyperlink overthe internet and/or intranet.
 16. The system in accordance with claim10, further comprising: a mechanism for automatically analyzing andrepresenting the topology of any arbitrary switched Ethernet.